Tail lamp generally refers to the lamps mounted on the back of vehicles, and the main color of tail lamps is usually red. The tail lamps may play different roles in different colors, for example, a red brake lamp (width lamp) is used to alert following vehicles, an amber turn lamp is used to indicate directions, and a white reversing lamp is used to serve as an auxiliary observation.
Existing tail lamps generally use light-emitting diodes (LEDs) as light source, as shown in FIG. 1. Since LED light source is a point light source, an optical pattern generated by a LED light source can be a halo pattern which includes a bright region and a dark region. The bright region is at a relatively central position, and the dark region is near the edge of the halo pattern, outside the bright region. The light intensity presented by the optical pattern will be proportionally and gradually increased from outside to inside in a direction of X-axis or Y-axis.
However, in the prior art, such tail lamps can only present a circular shape with brightness gradually changing from center to outer edge, which cannot meet the diversified requirements of the optical effect design of the automobile tail lamps.